Maximum microbes

The frontier of the life sciences now lies in unsavoury places that Mother taught us to abhor: in the human gut, in dust gathering in corners, in the stains and grime on computer keyboards. A small sample from such habitats may contain more microbes than the entire human population. It’s a new Wild West waiting for the next gold rush in the life sciences.

This is the domain of microbial ecology, which spun off from microbiology long ago but acquired speed only recently. While the parent science is founded on taxonomy, the ordering of life forms into genus, species, variety and strain, microbial ecology looks at organisms in the context of the minute ecosystems they inhabit, and studies how they interact with each other and with other life forms, such as humans.

Bacteria and fungi have been used in the food and beverage industry for millennia, and the study of Penicillium altered the practice of medicine altogether. Recent innovations include the use of hydrocarbonoclastic bacteria like Thalassolituus and Alcanivorax to degrade oil spills, but the economic possibilities have barely been tapped. Though microbes are the most numerous life forms —a pinch of soil may contain tens of millions—only a small minority have been studied exhaustively. If the proteins of one microbe trigger asthma, another may prevent attacks. While some bacteria crack oil spills, so far unappreciated species could clean up the interiors of refrigerators and cars, storehouses of infection in modern times. Forensics can get a leg up with the recent discovery, at the University of Colorado at Boulder, that our fingertips leave behind personal microbial signatures on objects they touch. This could find use in the courtrooms and police labs of the near future, supplementing the use of fingerprints and genetic material.

The idea of using microbes, usually bacteria, to better our lives could be as old as human civilisation. By Roman times, fermented foods were a permanent feature of European cuisine. Wine and cheese were promoted for their health benefits and the Romans especially prized a fish sauce called garum. Made from fish guts fermented in sunlit sea water, it had to be produced in factories far away from human habitations for reasons of public sanitation and even sanity, but appeared to have medicinal qualities nevertheless.

The technologies of fermented food and drink derived from artisanal traditions and were probably developed in the commons by trial and error, without a clear understanding